Form for concrete girder construction.



c. M. MARKHAM.

FORM FOR CONCRETE GIRDER CONSTRUCT|0N.

1,200,124 APPLICATION FILED JUNE 30. 1910. Patented Oct 3,

2 SHEETS-SHEET l.

llllll IIIIX| c. M. MARKHAM. FORM FOR CONCRETE GIRDER CONSTRUCTION.

APPLICATION FILED JUNE 30, I910 Patented Oct. 3

2 SHEETS-SHEET 2.

I I I 6&M.

m: uamz-s runes cu. FNOYB urnn STA ' S PAT CHARLES 1vr. MAKKHAIVI, or on'grcaeo, ILLINOIS.

FORM non co vcRETE emn'nit'c'onsrnuorroiv.

Specification of Letters Patent.

Patented Oct. 3, 1916.

Application filed June 30, 1910. Serial no. 569,643.

To all whom it may concern Be it known that I, CHARLES M. MARK- HAM, a citizen of the United States, residing at Chicago, in the county of Cook and'State of Illinois, have invented certain new and useful Improvements in Forms for Concrete Girder Construction, of which the following is a description My invention relates to mechanism for controlling the general form and position of the forms for constructing concrete girders and the like. I

The object of my invention is to provide a simple, convenient and efiicient devlce of the kind described, capable of accurate adjustment, yet so constructed in all of its parts that the necessarily rough treatment to which it is often subjected will not seriously impair its efliciency or operativeness.

To this end my invention consists in the.

Fig. 1. Fig. 5 is a section taken substan-' tially on line 5-5 of Fig. 4. Fig. 6 is an enlarged section taken substantially on line 66 of Fig. 1. Fig. 7 is a perspective detail of a portion of my device.

I11 the preferred construction shown in the drawings, my device consists of a rectangular timber of up-right 1 of suitable length to form a support for the operative parts of my device. A cross arm 2 is provided'at the upper end of the up-right extending substantially an equal distance at each side thereof, and provided with suitable braces 33 or other convenient meansv for rigidly maintaining the cross arm in a horizontal position. i

Suitable means are provided'for adjustably securing the cross arm to the up-right. As shown a U shaped staple 4 is. provided having both of its arms 14 threaded and eachprovided with a nut 5. A collar 6 is formed upon or secured to each arm 4 near the connecting portlon between the arms,

and a pair ofplates 7 and 8 are provided, each having a sultable opening near lts eX-' tremities to receive the arms%1-4 and serve' as a clamp for securing the cross arm and up-righttogether. The distance between the arms 4 is suflicient to receive'the end of the up-r'ightbetween them. One of the plates 7 is positioned at the front of the cross arm 2, and the arms 4; extend through the plate 7 and cross arm 2'along each side of the upper end-of the up-right and through'the plate 8 so that by adjusting the nuts 5 the cross arm I 2 will befirmly clamped-to the up-right 1. Its position may however be adjusted upon theup-right as desiredto accommodate any slight variations in the height of the girder above the base upon which my device is resting. I p

The braces 8'3 are preferably each ri idly secured to the cross arm 2 near its eX- tremities and extend downward to the up right 1 where a staple 1 similar to the staple f1 is provided with its arms 4 preferably extending through the end portions of the braces 3 to rigidly and adjustably clamp them to the upright The bottom or lower member 9 of the girder form preferably rests directly upon the cross arm 2 and the side members 10 -10 of the form are forced against the sides of the bottom member and rigidly held in position by a pair of channel bars 111'1 adjustably connected to, and supported by, the cross arm 2.

Any suitable means may be provided for adjustably attaching the bars 1111 to the cross arm 2. In the form shown a member 12 is provided, having a hook 14,. adapted to slidably engage the cross arm. The bot-' tom portion of the member 12 is tubular and of suitable form to receive the bar 11 and admit of its free longitudinal movement therethrough. Laterally projecting ears or lugs 15 are provided upon the member 12 suitably spaced from each other to receive a boltl6, which is pivotally .attached to the staple 4: between them. In the preferred construction the lugs15 eachyha-ve a fiat bearing surface for a washer 17 at right angles to the bolt 16 with a projecting rib 18 at the outer edge of each, adapted to engage the straight side .of the washer 17 to control its position and prevent "itsrotation with the nut 19 as shown in Fig. 2. The transverse position of the lower end of the bars 11 may be controlled in any suitable manner. As shown a series of notches 2323 are provided in the inner flange of the channel bar 11 and a member 22 is pro vided, having a part adapted to rest against the faceand inner flange of the bar 11 with a part 24 suitably formed to engage any of 7 adjusted position. A cotter pin 27 is provided in a suitable transverse opening near the extremity of the bolt 20 so that when the part 22 is disengaged from the bar 11 it will not escape from the bolt. 7

The vertical position ofthe bar 11 may be controlled in any suitable manner. In the form shown a part 30 is provided upon the.

member 12 having a jaw 32 'pivotally mounted at its lower end and arranged to freely adjust itself transversely of the part 30 and to cramp upon the bar 11 to prevent its downward movement, the parts being so formed that the bar 11 is free to be moved upward as desired, but will be automatically locked against downward movement and held in position by the aw 32. V V In the preferred construction suitable means are provided at the upper end of the bar 11 to engage and support any joistsor other floor or. ceiling members in their proper position 1n relation to the girder being formed. In the preferred construction shown a part 35, arranged to cooperate with V the upper part of the bar ll to form a jaw'is rigidly attached to the bar 11 by suitable rivets 36 or other convenient means.

laterally so that when the part 35 is in position it'will be wedged betweenthe flanges of the bar 11 and accurately and rigidly held in position. Obviously where a girder is employed for supporting a floor or ceiling, it would be inconvenient to provide one of my devices for each of. the joists to be supported by the girder. For this purpose a stirrup 40, as shownin Fig. 7 is provided Copies of this patent may be obtained'for T e portion of the part 35 positioned between the flanges of the bar 11 is preferably beveled having one end 41 formed to engage and fit between the flanges of thebeam 11 and of the beam preferably corresponding to the length of the part 40, so that the top surface of the beam will accurately correspond with the top surface of the part 41 and the several joists resting upon the beam 43 will be accurately alined horizontally. When in operation the several parts are suitably positioned upon the up-right and brought to the proper level to support the bottom member of the form, the bars 11 are then adjusted to the proper elevation to support the joists and adjusted transversely to supportrthe side members 10-10 of'the form, which may then be filled in the usual or any preferred manner.

Having thus described my invention it is obvious that various immaterial modifications may be made in my device without de parting from the spirit of my invention,

hence I do not wish to be understood as limiting myself to the exact form or construction shown.

What I claim as new and desire to secure by Letters Patent is:

In a device of the kind described, a channel bar provided with a jaw at its upper end adapted to loosely engage a horizontal beam to support the same in position, in combination with a part'adapted to engage said jaw and interlock therewith to prevent lateral disengagement, said part being adapted to support ,a'second beam in fixed relation to said first beam.

In testimony whereof, I have hereunto signed. my name'in the presence of two subscribingwitnesses. I l V 7 CHARLES M. MARKHAM.

Witnesses:

BLANCHE CHALMERS, s BURTON U. HILLS.

five cents each, by addressing the Commissionerof Patents, Washington, D. G. 

